For those of you who runs into stagnant residential supply lines, either as a plumber being called in or in a remodel/rehab where you know the property has been vacant for a while, and water has even been shutoff due to non payment, perhaps a foreclosured abandoned property, where water has not been used for months, or years. This mean you have stagnant water in the supply system with the Legionella bacteria.

Just curious once you have the water turned back on, what are your procedure to flush the system out if you know it hasn’t been used for a long time?

My understanding is if you just say turn a hose bib on outside the water would jet out with the bacteria into the air and into your lungs. Same if you say have a broken stop valve inside and you have to cut the pipe to replace the valve or run the water through the tub/shower valve to the shower head.

Do you do anything different to minimize your exposure to Legionella in those situations?